1 /* 2 * Copyright 2011 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "SkPDFUtils.h" 9 10 #include "SkData.h" 11 #include "SkFixed.h" 12 #include "SkGeometry.h" 13 #include "SkImage_Base.h" 14 #include "SkPDFResourceDict.h" 15 #include "SkPDFTypes.h" 16 #include "SkStream.h" 17 #include "SkString.h" 18 19 #include <cmath> 20 21 sk_sp<SkPDFArray> SkPDFUtils::RectToArray(const SkRect& rect) { 22 auto result = sk_make_sp<SkPDFArray>(); 23 result->reserve(4); 24 result->appendScalar(rect.fLeft); 25 result->appendScalar(rect.fTop); 26 result->appendScalar(rect.fRight); 27 result->appendScalar(rect.fBottom); 28 return result; 29 } 30 31 sk_sp<SkPDFArray> SkPDFUtils::MatrixToArray(const SkMatrix& matrix) { 32 SkScalar values[6]; 33 if (!matrix.asAffine(values)) { 34 SkMatrix::SetAffineIdentity(values); 35 } 36 37 auto result = sk_make_sp<SkPDFArray>(); 38 result->reserve(6); 39 for (size_t i = 0; i < SK_ARRAY_COUNT(values); i++) { 40 result->appendScalar(values[i]); 41 } 42 return result; 43 } 44 45 // static 46 void SkPDFUtils::AppendTransform(const SkMatrix& matrix, SkWStream* content) { 47 SkScalar values[6]; 48 if (!matrix.asAffine(values)) { 49 SkMatrix::SetAffineIdentity(values); 50 } 51 for (size_t i = 0; i < SK_ARRAY_COUNT(values); i++) { 52 SkPDFUtils::AppendScalar(values[i], content); 53 content->writeText(" "); 54 } 55 content->writeText("cm\n"); 56 } 57 58 // static 59 void SkPDFUtils::MoveTo(SkScalar x, SkScalar y, SkWStream* content) { 60 SkPDFUtils::AppendScalar(x, content); 61 content->writeText(" "); 62 SkPDFUtils::AppendScalar(y, content); 63 content->writeText(" m\n"); 64 } 65 66 // static 67 void SkPDFUtils::AppendLine(SkScalar x, SkScalar y, SkWStream* content) { 68 SkPDFUtils::AppendScalar(x, content); 69 content->writeText(" "); 70 SkPDFUtils::AppendScalar(y, content); 71 content->writeText(" l\n"); 72 } 73 74 // static 75 void SkPDFUtils::AppendCubic(SkScalar ctl1X, SkScalar ctl1Y, 76 SkScalar ctl2X, SkScalar ctl2Y, 77 SkScalar dstX, SkScalar dstY, SkWStream* content) { 78 SkString cmd("y\n"); 79 SkPDFUtils::AppendScalar(ctl1X, content); 80 content->writeText(" "); 81 SkPDFUtils::AppendScalar(ctl1Y, content); 82 content->writeText(" "); 83 if (ctl2X != dstX || ctl2Y != dstY) { 84 cmd.set("c\n"); 85 SkPDFUtils::AppendScalar(ctl2X, content); 86 content->writeText(" "); 87 SkPDFUtils::AppendScalar(ctl2Y, content); 88 content->writeText(" "); 89 } 90 SkPDFUtils::AppendScalar(dstX, content); 91 content->writeText(" "); 92 SkPDFUtils::AppendScalar(dstY, content); 93 content->writeText(" "); 94 content->writeText(cmd.c_str()); 95 } 96 97 static void append_quad(const SkPoint quad[], SkWStream* content) { 98 SkPoint cubic[4]; 99 SkConvertQuadToCubic(quad, cubic); 100 SkPDFUtils::AppendCubic(cubic[1].fX, cubic[1].fY, cubic[2].fX, cubic[2].fY, 101 cubic[3].fX, cubic[3].fY, content); 102 } 103 104 // static 105 void SkPDFUtils::AppendRectangle(const SkRect& rect, SkWStream* content) { 106 // Skia has 0,0 at top left, pdf at bottom left. Do the right thing. 107 SkScalar bottom = SkMinScalar(rect.fBottom, rect.fTop); 108 109 SkPDFUtils::AppendScalar(rect.fLeft, content); 110 content->writeText(" "); 111 SkPDFUtils::AppendScalar(bottom, content); 112 content->writeText(" "); 113 SkPDFUtils::AppendScalar(rect.width(), content); 114 content->writeText(" "); 115 SkPDFUtils::AppendScalar(rect.height(), content); 116 content->writeText(" re\n"); 117 } 118 119 // static 120 void SkPDFUtils::EmitPath(const SkPath& path, SkPaint::Style paintStyle, 121 bool doConsumeDegerates, SkWStream* content, 122 SkScalar tolerance) { 123 // Filling a path with no area results in a drawing in PDF renderers but 124 // Chrome expects to be able to draw some such entities with no visible 125 // result, so we detect those cases and discard the drawing for them. 126 // Specifically: moveTo(X), lineTo(Y) and moveTo(X), lineTo(X), lineTo(Y). 127 128 SkRect rect; 129 bool isClosed; // Both closure and direction need to be checked. 130 SkPath::Direction direction; 131 if (path.isRect(&rect, &isClosed, &direction) && 132 isClosed && 133 (SkPath::kCW_Direction == direction || 134 SkPath::kEvenOdd_FillType == path.getFillType())) 135 { 136 SkPDFUtils::AppendRectangle(rect, content); 137 return; 138 } 139 140 enum SkipFillState { 141 kEmpty_SkipFillState, 142 kSingleLine_SkipFillState, 143 kNonSingleLine_SkipFillState, 144 }; 145 SkipFillState fillState = kEmpty_SkipFillState; 146 //if (paintStyle != SkPaint::kFill_Style) { 147 // fillState = kNonSingleLine_SkipFillState; 148 //} 149 SkPoint lastMovePt = SkPoint::Make(0,0); 150 SkDynamicMemoryWStream currentSegment; 151 SkPoint args[4]; 152 SkPath::Iter iter(path, false); 153 for (SkPath::Verb verb = iter.next(args, doConsumeDegerates); 154 verb != SkPath::kDone_Verb; 155 verb = iter.next(args, doConsumeDegerates)) { 156 // args gets all the points, even the implicit first point. 157 switch (verb) { 158 case SkPath::kMove_Verb: 159 MoveTo(args[0].fX, args[0].fY, ¤tSegment); 160 lastMovePt = args[0]; 161 fillState = kEmpty_SkipFillState; 162 break; 163 case SkPath::kLine_Verb: 164 AppendLine(args[1].fX, args[1].fY, ¤tSegment); 165 if ((fillState == kEmpty_SkipFillState) && (args[0] != lastMovePt)) { 166 fillState = kSingleLine_SkipFillState; 167 break; 168 } 169 fillState = kNonSingleLine_SkipFillState; 170 break; 171 case SkPath::kQuad_Verb: 172 append_quad(args, ¤tSegment); 173 fillState = kNonSingleLine_SkipFillState; 174 break; 175 case SkPath::kConic_Verb: { 176 SkAutoConicToQuads converter; 177 const SkPoint* quads = converter.computeQuads(args, iter.conicWeight(), tolerance); 178 for (int i = 0; i < converter.countQuads(); ++i) { 179 append_quad(&quads[i * 2], ¤tSegment); 180 } 181 fillState = kNonSingleLine_SkipFillState; 182 } break; 183 case SkPath::kCubic_Verb: 184 AppendCubic(args[1].fX, args[1].fY, args[2].fX, args[2].fY, 185 args[3].fX, args[3].fY, ¤tSegment); 186 fillState = kNonSingleLine_SkipFillState; 187 break; 188 case SkPath::kClose_Verb: 189 ClosePath(¤tSegment); 190 currentSegment.writeToStream(content); 191 currentSegment.reset(); 192 break; 193 default: 194 SkASSERT(false); 195 break; 196 } 197 } 198 if (currentSegment.bytesWritten() > 0) { 199 currentSegment.writeToStream(content); 200 } 201 } 202 203 // static 204 void SkPDFUtils::ClosePath(SkWStream* content) { 205 content->writeText("h\n"); 206 } 207 208 // static 209 void SkPDFUtils::PaintPath(SkPaint::Style style, SkPath::FillType fill, 210 SkWStream* content) { 211 if (style == SkPaint::kFill_Style) { 212 content->writeText("f"); 213 } else if (style == SkPaint::kStrokeAndFill_Style) { 214 content->writeText("B"); 215 } else if (style == SkPaint::kStroke_Style) { 216 content->writeText("S"); 217 } 218 219 if (style != SkPaint::kStroke_Style) { 220 NOT_IMPLEMENTED(fill == SkPath::kInverseEvenOdd_FillType, false); 221 NOT_IMPLEMENTED(fill == SkPath::kInverseWinding_FillType, false); 222 if (fill == SkPath::kEvenOdd_FillType) { 223 content->writeText("*"); 224 } 225 } 226 content->writeText("\n"); 227 } 228 229 // static 230 void SkPDFUtils::StrokePath(SkWStream* content) { 231 SkPDFUtils::PaintPath( 232 SkPaint::kStroke_Style, SkPath::kWinding_FillType, content); 233 } 234 235 // static 236 void SkPDFUtils::DrawFormXObject(int objectIndex, SkWStream* content) { 237 content->writeText("/"); 238 content->writeText(SkPDFResourceDict::getResourceName( 239 SkPDFResourceDict::kXObject_ResourceType, 240 objectIndex).c_str()); 241 content->writeText(" Do\n"); 242 } 243 244 // static 245 void SkPDFUtils::ApplyGraphicState(int objectIndex, SkWStream* content) { 246 content->writeText("/"); 247 content->writeText(SkPDFResourceDict::getResourceName( 248 SkPDFResourceDict::kExtGState_ResourceType, 249 objectIndex).c_str()); 250 content->writeText(" gs\n"); 251 } 252 253 // static 254 void SkPDFUtils::ApplyPattern(int objectIndex, SkWStream* content) { 255 // Select Pattern color space (CS, cs) and set pattern object as current 256 // color (SCN, scn) 257 SkString resourceName = SkPDFResourceDict::getResourceName( 258 SkPDFResourceDict::kPattern_ResourceType, 259 objectIndex); 260 content->writeText("/Pattern CS/Pattern cs/"); 261 content->writeText(resourceName.c_str()); 262 content->writeText(" SCN/"); 263 content->writeText(resourceName.c_str()); 264 content->writeText(" scn\n"); 265 } 266 267 size_t SkPDFUtils::ColorToDecimal(uint8_t value, char result[5]) { 268 if (value == 255 || value == 0) { 269 result[0] = value ? '1' : '0'; 270 result[1] = '\0'; 271 return 1; 272 } 273 // int x = 0.5 + (1000.0 / 255.0) * value; 274 int x = SkFixedRoundToInt((SK_Fixed1 * 1000 / 255) * value); 275 result[0] = '.'; 276 for (int i = 3; i > 0; --i) { 277 result[i] = '0' + x % 10; 278 x /= 10; 279 } 280 int j; 281 for (j = 3; j > 1; --j) { 282 if (result[j] != '0') { 283 break; 284 } 285 } 286 result[j + 1] = '\0'; 287 return j + 1; 288 } 289 290 void SkPDFUtils::AppendScalar(SkScalar value, SkWStream* stream) { 291 char result[kMaximumFloatDecimalLength]; 292 size_t len = SkPDFUtils::FloatToDecimal(SkScalarToFloat(value), result); 293 SkASSERT(len < kMaximumFloatDecimalLength); 294 stream->write(result, len); 295 } 296 297 // Return pow(10.0, e), optimized for common cases. 298 inline double pow10(int e) { 299 switch (e) { 300 case 0: return 1.0; // common cases 301 case 1: return 10.0; 302 case 2: return 100.0; 303 case 3: return 1e+03; 304 case 4: return 1e+04; 305 case 5: return 1e+05; 306 case 6: return 1e+06; 307 case 7: return 1e+07; 308 case 8: return 1e+08; 309 case 9: return 1e+09; 310 case 10: return 1e+10; 311 case 11: return 1e+11; 312 case 12: return 1e+12; 313 case 13: return 1e+13; 314 case 14: return 1e+14; 315 case 15: return 1e+15; 316 default: 317 if (e > 15) { 318 double value = 1e+15; 319 while (e-- > 15) { value *= 10.0; } 320 return value; 321 } else { 322 SkASSERT(e < 0); 323 double value = 1.0; 324 while (e++ < 0) { value /= 10.0; } 325 return value; 326 } 327 } 328 } 329 330 /** Write a string into result, includeing a terminating '\0' (for 331 unit testing). Return strlen(result) (for SkWStream::write) The 332 resulting string will be in the form /[-]?([0-9]*.)?[0-9]+/ and 333 sscanf(result, "%f", &x) will return the original value iff the 334 value is finite. This function accepts all possible input values. 335 336 Motivation: "PDF does not support [numbers] in exponential format 337 (such as 6.02e23)." Otherwise, this function would rely on a 338 sprintf-type function from the standard library. */ 339 size_t SkPDFUtils::FloatToDecimal(float value, 340 char result[kMaximumFloatDecimalLength]) { 341 /* The longest result is -FLT_MIN. 342 We serialize it as "-.0000000000000000000000000000000000000117549435" 343 which has 48 characters plus a terminating '\0'. */ 344 345 /* section C.1 of the PDF1.4 spec (http://goo.gl/0SCswJ) says that 346 most PDF rasterizers will use fixed-point scalars that lack the 347 dynamic range of floats. Even if this is the case, I want to 348 serialize these (uncommon) very small and very large scalar 349 values with enough precision to allow a floating-point 350 rasterizer to read them in with perfect accuracy. 351 Experimentally, rasterizers such as pdfium do seem to benefit 352 from this. Rasterizers that rely on fixed-point scalars should 353 gracefully ignore these values that they can not parse. */ 354 char* output = &result[0]; 355 const char* const end = &result[kMaximumFloatDecimalLength - 1]; 356 // subtract one to leave space for '\0'. 357 358 /* This function is written to accept any possible input value, 359 including non-finite values such as INF and NAN. In that case, 360 we ignore value-correctness and and output a syntacticly-valid 361 number. */ 362 if (value == SK_FloatInfinity) { 363 value = FLT_MAX; // nearest finite float. 364 } 365 if (value == SK_FloatNegativeInfinity) { 366 value = -FLT_MAX; // nearest finite float. 367 } 368 if (!std::isfinite(value) || value == 0.0f) { 369 // NAN is unsupported in PDF. Always output a valid number. 370 // Also catch zero here, as a special case. 371 *output++ = '0'; 372 *output = '\0'; 373 return output - result; 374 } 375 if (value < 0.0) { 376 *output++ = '-'; 377 value = -value; 378 } 379 SkASSERT(value >= 0.0f); 380 381 int binaryExponent; 382 (void)std::frexp(value, &binaryExponent); 383 static const double kLog2 = 0.3010299956639812; // log10(2.0); 384 int decimalExponent = static_cast<int>(std::floor(kLog2 * binaryExponent)); 385 int decimalShift = decimalExponent - 8; 386 double power = pow10(-decimalShift); 387 int32_t d = static_cast<int32_t>(value * power + 0.5); 388 // SkASSERT(value == (float)(d * pow(10.0, decimalShift))); 389 SkASSERT(d <= 999999999); 390 if (d > 167772159) { // floor(pow(10,1+log10(1<<24))) 391 // need one fewer decimal digits for 24-bit precision. 392 decimalShift = decimalExponent - 7; 393 // SkASSERT(power * 0.1 = pow10(-decimalShift)); 394 // recalculate to get rounding right. 395 d = static_cast<int32_t>(value * (power * 0.1) + 0.5); 396 SkASSERT(d <= 99999999); 397 } 398 while (d % 10 == 0) { 399 d /= 10; 400 ++decimalShift; 401 } 402 SkASSERT(d > 0); 403 // SkASSERT(value == (float)(d * pow(10.0, decimalShift))); 404 uint8_t buffer[9]; // decimal value buffer. 405 int bufferIndex = 0; 406 do { 407 buffer[bufferIndex++] = d % 10; 408 d /= 10; 409 } while (d != 0); 410 SkASSERT(bufferIndex <= (int)sizeof(buffer) && bufferIndex > 0); 411 if (decimalShift >= 0) { 412 do { 413 --bufferIndex; 414 *output++ = '0' + buffer[bufferIndex]; 415 } while (bufferIndex); 416 for (int i = 0; i < decimalShift; ++i) { 417 *output++ = '0'; 418 } 419 } else { 420 int placesBeforeDecimal = bufferIndex + decimalShift; 421 if (placesBeforeDecimal > 0) { 422 while (placesBeforeDecimal-- > 0) { 423 --bufferIndex; 424 *output++ = '0' + buffer[bufferIndex]; 425 } 426 *output++ = '.'; 427 } else { 428 *output++ = '.'; 429 int placesAfterDecimal = -placesBeforeDecimal; 430 while (placesAfterDecimal-- > 0) { 431 *output++ = '0'; 432 } 433 } 434 while (bufferIndex > 0) { 435 --bufferIndex; 436 *output++ = '0' + buffer[bufferIndex]; 437 if (output == end) { 438 break; // denormalized: don't need extra precision. 439 // Note: denormalized numbers will not have the same number of 440 // significantDigits, but do not need them to round-trip. 441 } 442 } 443 } 444 SkASSERT(output <= end); 445 *output = '\0'; 446 return output - result; 447 } 448 449 void SkPDFUtils::WriteString(SkWStream* wStream, const char* cin, size_t len) { 450 SkDEBUGCODE(static const size_t kMaxLen = 65535;) 451 SkASSERT(len <= kMaxLen); 452 453 size_t extraCharacterCount = 0; 454 for (size_t i = 0; i < len; i++) { 455 if (cin[i] > '~' || cin[i] < ' ') { 456 extraCharacterCount += 3; 457 } 458 if (cin[i] == '\\' || cin[i] == '(' || cin[i] == ')') { 459 ++extraCharacterCount; 460 } 461 } 462 if (extraCharacterCount <= len) { 463 wStream->writeText("("); 464 for (size_t i = 0; i < len; i++) { 465 if (cin[i] > '~' || cin[i] < ' ') { 466 uint8_t c = static_cast<uint8_t>(cin[i]); 467 uint8_t octal[4]; 468 octal[0] = '\\'; 469 octal[1] = '0' + ( c >> 6 ); 470 octal[2] = '0' + ((c >> 3) & 0x07); 471 octal[3] = '0' + ( c & 0x07); 472 wStream->write(octal, 4); 473 } else { 474 if (cin[i] == '\\' || cin[i] == '(' || cin[i] == ')') { 475 wStream->writeText("\\"); 476 } 477 wStream->write(&cin[i], 1); 478 } 479 } 480 wStream->writeText(")"); 481 } else { 482 wStream->writeText("<"); 483 for (size_t i = 0; i < len; i++) { 484 uint8_t c = static_cast<uint8_t>(cin[i]); 485 char hexValue[2] = { SkHexadecimalDigits::gUpper[c >> 4], 486 SkHexadecimalDigits::gUpper[c & 0xF] }; 487 wStream->write(hexValue, 2); 488 } 489 wStream->writeText(">"); 490 } 491 } 492 493 bool SkPDFUtils::InverseTransformBBox(const SkMatrix& matrix, SkRect* bbox) { 494 SkMatrix inverse; 495 if (!matrix.invert(&inverse)) { 496 return false; 497 } 498 inverse.mapRect(bbox); 499 return true; 500 } 501 502 void SkPDFUtils::PopulateTilingPatternDict(SkPDFDict* pattern, 503 SkRect& bbox, 504 sk_sp<SkPDFDict> resources, 505 const SkMatrix& matrix) { 506 const int kTiling_PatternType = 1; 507 const int kColoredTilingPattern_PaintType = 1; 508 const int kConstantSpacing_TilingType = 1; 509 510 pattern->insertName("Type", "Pattern"); 511 pattern->insertInt("PatternType", kTiling_PatternType); 512 pattern->insertInt("PaintType", kColoredTilingPattern_PaintType); 513 pattern->insertInt("TilingType", kConstantSpacing_TilingType); 514 pattern->insertObject("BBox", SkPDFUtils::RectToArray(bbox)); 515 pattern->insertScalar("XStep", bbox.width()); 516 pattern->insertScalar("YStep", bbox.height()); 517 pattern->insertObject("Resources", std::move(resources)); 518 if (!matrix.isIdentity()) { 519 pattern->insertObject("Matrix", SkPDFUtils::MatrixToArray(matrix)); 520 } 521 } 522 523 bool SkPDFUtils::ToBitmap(const SkImage* img, SkBitmap* dst) { 524 SkASSERT(img); 525 SkASSERT(dst); 526 SkBitmap bitmap; 527 if(as_IB(img)->getROPixels(&bitmap, nullptr)) { 528 SkASSERT(bitmap.dimensions() == img->dimensions()); 529 SkASSERT(!bitmap.drawsNothing()); 530 *dst = std::move(bitmap); 531 return true; 532 } 533 return false; 534 } 535
